Martha Davis: 'Oral argument only makes a difference in the outcome of 5% of the cases before the court'

Tuesday's argument on the individual mandate portion of the ACA went very well for opponents of the healthcare law. Paul Clement, representing the states, is a brilliant oralist, and he gave a bravura presentation of the states' argument. The questions for the government were pointed and, like almost all of the other lawyers in the country, US Solicitor General Verrilli simply doesn't have Clement's flare. But there's far from enough here to declare winners or losers at this point.

The votes in play are those of Chief Justice Roberts, and Justices Kennedy and Alito. As for the other justices, their questioning suggests that Breyer, Ginsburg, Kagan and Sotomayor will likely favor the law, and Scalia will very likely to strike down the mandate. Justice Thomas, silent as usual during oral argument, is also likely to oppose the individual mandate.

What, then, to make of the questions raised by the three justices in the middle? Chief Justice Roberts is notoriously hard to read during oral argument, and he genuinely seems to test out arguments on oralists in order to clarify his own thinking, without revealing his orientation. Justice Kennedy asked hard questions of both sides, suggesting that he is still grappling with the difficult issues in the case. Of these three, Justice Alito gave the strongest impression of leaning against the individual mandate.

It would be foolish, though, to predict the outcome by looking just at the questions during oral argument. An important source of information here is these justices' past records. As recently as 2010, these same three justices – Roberts, Kennedy and Alito – all voted to uphold a federal civil commitment statute that lacked explicit identification with an enumerated congressional power and that was most strongly supported by the broad necessary and proper clause. In fact, Chief Justice Roberts joined Justice Breyer's majority opinion upholding the law.

With this in mind, perhaps, Chief Justice Roberts seemed to recognize through his questioning Tuesday that it would be difficult to reconcile a vote against the individual mandate with the prior decisions of the court and the court's historic deference to the elected branches.

A former US solicitor general once told me that, in his opinion, oral argument only makes a difference in the outcome of 5% of the cases before the US supreme court. The oral argument is the public face of the case, sure, but it's important to remember that it is just the tip of the iceberg when it comes to the material that will contribute to the court's decision – particularly in a case like this, with 136 amicus briefs.

Martha F Davis teaches constitutional law at Northeastern University school of law

Scott Lemieux: 'If Kennedy was not satisfied by the answers given by the government, the ACA is in real trouble'

To the increasing number of legal observers who see the supreme court upholding the Affordable Care Act as a near certainty, Tuesday's oral arguments may be a surprise. My own take is that this is a very close case that will almost certainly come down to the court's typical median vote, Justice Anthony Kennedy. Because Kennedy is sympathetic both to economic libertarianism and limiting federal power, but is not as strong a proponent for these views as his colleague Clarence Thomas, his vote could go either way.

Tuesday's oral arguments did not leave me much more confident about predicting Kennedy's crucial vote, but they do increase my conviction that his vote will be crucial. Three of the four most conservative votes on the court were notably hostile to the federal government's arguments, and the fourth (Clarence Thomas, who almost never speaks at oral argument) is as mentioned an almost definite vote to rule the ACA's individual mandate unconstitutional.

Chief Justice Roberts could conceivably be a sixth vote to uphold – the chief justice surrenders his power to assign the opinion if he joins with the dissenters, and if Kennedy's vote is lost, he may decide to try to moderate the opinion upholding the statute – but I think it's highly unlikely that he would be a fifth.

If Kennedy's vote is lost, the Obama administration's signature domestic legislative achievement will be rendered unworkable or struck down entirely. Kennedy was a little more critical of those who are challenging the constitutionality of the law than his fellow Republican appointees, so it is hard to say which way he's leaning.

The key point for Kennedy appears to be reflected in his question, "Can you identify for us some limits on the commerce clause?" Kennedy seems to be seeking reassurance that there is a "limiting principle", something in the government's position that will prevent its interpretation of the commerce clause from being an unlimited grant of federal power. Broken up by other questions, Solicitor General Donald Verrilli Jnr did not give the clearest possible answer to this query.

I believe that there are two good answers to Kennedy's question, one of which would almost certainly not satisfy him, but the other of which might. My first answer would be to echo James Madison and say that the cumbersome legislative process established by the constitution is itself a powerful "limiting principle". To worry about whether the federal government will make you purchase broccoli (or, as Chief Justice Roberts suggested today, a cellphone) is silly because political constraints will prevent this from happening. Even federal powers that nobody disputes can be used to pass silly or intrusive policies; and even if one passes, it is not necessarily unconstitutional.

My second answer is that upholding the mandate would not threaten United States v Lopez, the 1995 case that struck down the Gun Free School Zones Act as exceeding the federal government's power to regulate interstate commerce. Unlike the individual mandate, this bill was not directly an economic regulation and was not an important part of a broader regulatory framework, and Congress provided no evidence of a substantial effect on the national economy. The supreme court has already established a "limiting principle", which upholding the ACA would not threaten.

The fact that I don't believe that the constitutional case against the ACA is strong, however, doesn't mean that a majority of the court will. It's possible that Kennedy was not satisfied by the answers given by the government. If he isn't, the ACA is in real trouble.

Scott Lemieux is a professor of political science at the College of Saint Rose, Albany, New York, and blogs for Lawyers, Guns and Money

Mark Hall: 'It appears that at least two conservative justices are potentially in play'

An hour before the start, the courtroom was filled with a buzz of excitement, and a who's who gallery of legal and political notables. Seated to my left and right were senior members of Congress. In front and behind me were famous constitutional legal scholars. And spread in the midst were bleary-eyed ordinary citizens who had camped out in line Monday night – despite the near-freezing temperature.

The government's lawyer got off to a slow start, stumbling for the right words and reaching for his water glass, even before the Republican-appointed justices pounced – which they did soon enough, and repeatedly. They peppered Solicitor General Donald Verrilli with deeply conservative concerns, such as whether the law's "individual mandate" reworks the fundamental "relation of the individual to the government" (per Justice Kennedy); and that, while perhaps "necessary", the mandate is not "proper" (per Justice Scalia) – because of its infringement of individual liberty.

The solicitor general was struggling sufficiently that it appeared several more liberal justices felt compelled to come to his rescue. Justices Breyer and Sotomayor, in particular, used questions to give an astute and powerful defence of the law.

Lawyers for the challengers spoke swiftly and confidently. They, too, met with well-prepared objections to their positions, but tellingly, not all those objections were from the Democratic appointees to the court. Justice Roberts asked the challengers to respond to specific positions of the government. And Justice Kennedy, in particular, appeared to have absorbed the subtler dimensions of the government's defence of the law. This is important since Justice Kennedy is considered to be a "swing" vote, whose views usually determine the outcome when a case is decided 5 to 4.

On balance, with four liberal justices appearing to be firmly in support of the law, the government needs to win over one of the five conservatives. Based on Tuesday's questioning, it appears that at least two of them (Kennedy and Roberts) are potentially in play. We await the final word, probably in late June.